A computer data item such as a file that contains the text of a book or an arrangement of data that represents an audio or video rendering or recording may be copied and distributed via removable media such as a floppy diskette or a CD-ROM or over a computer network such as the Internet. In some cases, a data item is intended to be copied and distributed freely, with little or no control over access to the data item. In other cases, control over access is attempted by physical means, such as by exercising some control over the number of pieces of removable media that are produced, or by copy protection methods that impede the ability of a computer to produce a copy of the data item.
As shown in FIG. 1, in existing electronic book distribution systems, a data item that represents the contents of a book (“book data”) is copied (e.g., across a network connection) from a central source to book reading devices (i.e., book viewing devices) in a hub-and-spoke arrangement.